CVE-2026-78206
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk37th percentile - higher than 37% of all known CVEs
Summary
The exceljs library through version 4.4.0 decompresses all entries from supplied xlsx archives into memory without limits on entry size, total size, or compression ratio. Attackers can upload highly compressed workbooks that expand to gigabytes in memory, exhausting available resources and causing denial of service.
Risk Assessment
The vulnerability can lead to memory exhaustion and application crashes, resulting in service unavailability for users. It can be exploited for DoS attacks.
Recommendation
Update the exceljs library to the latest version that includes a fix. Additionally, restrict the size of uploaded files and implement resource limits.
Other vulnerabilities in exceljs
See all- CVE-2026-78207Critical
The exceljs library through version 4.4.0 contains a prototype pollution vulnerability in the deepMerge helper that fails to reject __proto__, constructor, or prototype keys when merging note objects. Attackers can assign parsed JSON with a malicious __proto__ property to cell notes, modifying Object.prototype and affecting all plain objects created in the process.
- CVE-2026-78209High
The exceljs library through version 4.4.0 fails to neutralize leading equals, plus, minus, or at signs in cell values written to CSV output. Attackers who can influence exported cell values can inject formulas that execute when the CSV file is opened in a spreadsheet application, potentially exfiltrating data or performing other malicious actions.
- CVE-2026-78208High
The exceljs library through version 4.4.0 contains a path traversal vulnerability in the Workbook.addImage() function that fails to validate file paths. Attackers can supply arbitrary file paths to read any file accessible to the Node.js process and embed it in the generated workbook.
Original NVD description (English source)
exceljs through 4.4.0 decompresses all entries from supplied xlsx archives into memory without limits on entry size, total size, or compression ratio. Attackers can upload highly compressed workbooks that expand to gigabytes in memory, exhausting available resources and causing denial of service.